TY - JOUR
T1 - A chemically bonded monolayer interface enables enhanced thermal stability and efficiency in Pb-Sn perovskite solar cells
AU - Bati, Abdulaziz S.R.
AU - Liu, Cheng
AU - Gilley, Isaiah W.
AU - Musgrave, Charles B.
AU - Maxwell, Aidan
AU - Steele, Julian A.
AU - Yang, Yi
AU - Chen, Hao
AU - Wan, Haoyue
AU - Xu, Jian
AU - Solano, Eduardo
AU - Zhang, Rui
AU - Huang, Chuying
AU - Rehl, Benjamin
AU - Lempesis, Nikolaos
AU - Carnevali, Virginia
AU - Vezzosi, Andrea
AU - Zeng, Lewei
AU - Grater, Luke
AU - Li, Muzhi
AU - Rolston, Nicholas
AU - Choi, Deokjae
AU - Sláma, Vladislav
AU - Rothlisberger, Ursula
AU - Wang, Lianzhou
AU - Goddard, William A.
AU - Kanatzidis, Mercouri G.
AU - Chen, Bin
AU - Bakr, Osman M.
AU - Sargent, Edward H.
N1 - Publisher Copyright:
© 2025 Elsevier Inc.
PY - 2025/9/17
Y1 - 2025/9/17
N2 - Advances in narrow-band-gap (NBG) mixed lead-tin (Pb-Sn) perovskites have enabled increasingly efficient all-perovskite tandem solar cells, yet device stability remains limited by acidic poly(3,4-ethylenedioxythiophene) polystyrenesulfonate (PEDOT:PSS) hole transport materials (HTMs). Although carbazole-based self-assembled monolayers (SAMs) were considered as alternatives, they also degrade rapidly (T80 < 200 h) under external stresses. We identified weak chemical interaction at the transparent conductive oxide:SAM:perovskite interface and hypothesized that stronger binding could enhance stability. Introducing bifunctional SAMs with thiol groups established robust S-Pb chemical coordination, improving fracture energy by 30%. Replacing acidic phosphonic groups with milder carboxylic groups and optimizing SAM chain length led to selecting 16-mercaptohexadecanoic acid (16-MHDA), balancing coverage, energy alignment, and series resistance. This approach doubled photocarrier lifetime and increased thermal degradation resistance by 1.3×. Single-junction Pb-Sn cells achieved 24% power conversion efficiency (PCE) and encapsulated devices retained 80% efficiency after 680 h under 1-sun illumination at a heatsink temperature of 50°C.
AB - Advances in narrow-band-gap (NBG) mixed lead-tin (Pb-Sn) perovskites have enabled increasingly efficient all-perovskite tandem solar cells, yet device stability remains limited by acidic poly(3,4-ethylenedioxythiophene) polystyrenesulfonate (PEDOT:PSS) hole transport materials (HTMs). Although carbazole-based self-assembled monolayers (SAMs) were considered as alternatives, they also degrade rapidly (T80 < 200 h) under external stresses. We identified weak chemical interaction at the transparent conductive oxide:SAM:perovskite interface and hypothesized that stronger binding could enhance stability. Introducing bifunctional SAMs with thiol groups established robust S-Pb chemical coordination, improving fracture energy by 30%. Replacing acidic phosphonic groups with milder carboxylic groups and optimizing SAM chain length led to selecting 16-mercaptohexadecanoic acid (16-MHDA), balancing coverage, energy alignment, and series resistance. This approach doubled photocarrier lifetime and increased thermal degradation resistance by 1.3×. Single-junction Pb-Sn cells achieved 24% power conversion efficiency (PCE) and encapsulated devices retained 80% efficiency after 680 h under 1-sun illumination at a heatsink temperature of 50°C.
KW - hole-selective layer
KW - interfacial contact
KW - narrow band gap
KW - perovskite solar cells
KW - self-assembled monolayer
KW - thermal stability
UR - https://www.scopus.com/pages/publications/105010685375
U2 - 10.1016/j.joule.2025.102047
DO - 10.1016/j.joule.2025.102047
M3 - Article
AN - SCOPUS:105010685375
SN - 2542-4351
VL - 9
JO - Joule
JF - Joule
IS - 9
M1 - 102047
ER -